He was commenting on a report that his predecessor Datuk Seri Najib Abdul Razak had recently been slapped with an income tax bill of RM1.5 billion.

The LHDN has ordered Najib to pay the sum for undeclared taxable income from 2011 to 2017 when he received more than RM4 billion, including a RM2.6 billion donation from Saudi Arabia.

Mahathir claimed that when Najib was prime minister, certain people were saddled with huge tax bills when their taxes were backdated by 10 years.

“Of course that’s not legal. You can’t backdate when these people already paid their taxes according to the law,” he told reporters at the Parliament lobby.

Last year, Mahathir claimed that some individuals were forced by the previous government to pay more taxes than necessary.

On a separate matter, the prime minister said the government would sell more assets to trim national debt if it was necessary.

“But of course, we will sell land (only) to Malaysians, not to foreigners,” he added.

When it was pointed out that the opposition were critical of such sale, he retorted that “the opposition’s job is to oppose. The government’s job is to do what the government thinks is right”.

“They could oppose all they want,” he added.

The sale of government assets became the subject of a heated debate in Parliament when it was revealed that the Malaysian consulate building on Gloucester Road in Hong Kong had been sold for RM1.68 billion.